Convergence of Standard Definition/High Definition Television (SDTV/HDTV) and personal computer (PC) systems is a new promising category of products for emerging home and business multimedia markets.
Generally a HDTV Set Top Box (STB) has the same architecture as a PC specialized for HDTV viewing and uses the same or similar components to the PC, such as I/O devices, a TV tuner, connectors, cables, etc. An STB unit typically contains a TV tuner, a TV video chip containing a microprocessor, MPEG video and audio decoding and processing subsystems, a large high-speed video memory buffer and optionally a hard disk, a LAN interface, extensive I/O, etc.
The STB software architecture is similar to that of a PC with an operating system and a suite of video applications, as well as standard PC applications. A full-function STB unit can also run an operating system (usually Linux™ or Windows CET™), and additional specialized software applications controlling HDTV video and audio functions, etc.
HDTV video is generated from the signal received from a video source (satellite, over the air, cable, DVD, Hard Disk, Internet, etc.) by an HDTV video subsystem in order to generate images on TV screens.
HDTV Copy Protected Video (CPV) content is relatively easy to protect against copying in a closed STB environment by not allowing any user access to decompressed and decrypted HDTV video data. On the other hand, in an open PC environment it is much more difficult to protect against CPV copying. For that reason PC-based HDTV systems are difficult to be certified to receive CPV content over cable.
Both HDTV and PC digital video subsystems have very similar architecture, consisting of a video chip and video memory. While the HDTV and PC video chip each support particular features, they are very similar in overall function.
Users want convergence of PC graphics processing and HDTV graphics processing in a single unit so that PC and TV information can be viewed on a same screen. For example, with the advent of picture-in-picture functionality of TV sets, it is possible to consult statistics and results for a given sports competition, while watching live another sports competition. It would then be desirable that a single unit be able to access the Internet and download the latest statistics and results for the given competition and display them on the same screen on which a TV program is being displayed.
Similarly, PC units connected to the Internet can obtain Electronic TV Program Guide (EPG) data via an EPG web server site. It would be desirable for a user to be able to view the EPG data displayed on an HDTV displaying while watching some other TV programming.
Alternatively, it would be desirable that a user may receive and view a TV program, such as the national news, on a PC monitor display while, simultaneously writing an email or surfing the web in another window on the PC monitor display.